HR2 under combined stress conditions

The resuscitated strains achieved through the addition of resuscitation promoting factor (Rpf) hold significant promise as bio-inoculants for enhancing the bioremediation of polychlorinated biphenyls (PCBs). Nevertheless, the potential of these resuscitated strains to transition into a viable but non-culturable (VBNC) state, along with the specific stressors that initiate this transformation, remains to be comprehensively elucidated. In this study, a resuscitated strain HR2, obtained through Rpf amendment, was employed to investigate its survival strategies under combined stress involving low temperature (LT), and PCBs, in the absence and presence of heavy metals (HMs). Whole-genome analysis demonstrated that HR2, affiliated with Achromobacter, possessed 107 genes associated with the degradation of polycyclic aromatic compounds. Remarkably, HR2 exhibited effective degradation of Aroclor 1242 and robust resistance to stress induced by LT and PCBs, while maintaining its culturability. However, when exposed to the combined stress of LT, PCBs, and HMs, HR2 entered the VBNC state. This state was characterized by significant decreases in enzyme activities and notable morphological, physiological, and molecular alterations compared to normal cells. These findings uncovered the survival status of resuscitated strains under stressful conditions, thereby offering valuable insights for the development of effective bioremediation strategies.

"Patient dignity can be ensured by providing adequate health care": A phenomenological analysis on survival strategies of military nurses

Background

The devastating COVID-19 outbreak has considerably influenced basic human healthcare needs. Due to healthcare organizational limitations, workload, and a shortage of healthcare professionals, particularly military nurses in developing countries, faced critical situations in dealing with COVID-19 patients. However, little is known about the survival strategies military nurses used while caring for coronavirus-infected patients.

Aims

This study aimed to investigate the survival strategies that inspired military nurses to manage COVID-19 patients in Bangladesh.

Methods

This study employed the phenomenology of practice framework developed by Max van Manen. Fourteen military nurses were purposefully selected to participate in this study. Semi-structured online interviews were conducted individually from January to February 2023 in three divisional (Dhaka, Chittagong, and Sylhet) COVID-19 dedicated military hospitals in Bangladesh. The study was reported using the COREQ checklist. Audio-video sessions of discussions were recorded, analyzed, and transcribed verbatim. Dataset analysis was performed using thematic analysis.

Results

Eight themes were developed: (i) Nurses' self-strategies; (ii) colleagues' strategies; (iii) Nurse managers' strategies; (iv) Feelings about nursing ethical values; (v) Employers' strategies; (vi) Government strategies; (vii) Family members' strategies; (viii) Strategies of social people.

Conclusions

The study's findings would inspire healthcare professionals to use various survival strategies when facing critical clinical situations. Additionally, this study encourages nurses to develop survival skills to avoid depression, fear, and anxiety and to learn how to deal with work-related stress situations.

Selective pressure of arsenic and antimony co-contamination on microbial community in alkaline sediments

Although response of microbial community to arsenic (As) and antimony (Sb) co-contamination has been investigated in neutral and acidic environments, little is known in alkaline environment. Herein, the microbial response and survival strategies under the stress of As and Sb co-contamination were determined in the alkaline sediments. Elevated concentrations of As (13700 ± 5012 mg/kg) and Sb (10222 ± 1619 mg/kg) were introduced into the alkaline sediments by the mine drainage, which was partially adopted in the aquatic environment and resulted in a relatively lower contamination (As, 6633 ± 1707 mg/kg; Sb, 6108 ± 1095 mg/kg) in the downstream sediments. The microbial richness was significantly damaged and the microbial compositions were dramatically shifted by the As and Sb co-contamination. Metagenomic analysis shed light on the survival strategies of the microbes under the pressure of As and Sb co-contamination including metal oxidation coupled with denitrification, metal reduction, and metal resistance. The representative microbes were revealed in the sediments with higher (Halomonas) and lower (Thiobacillus, Hydrogenophaga and Flavihumibacter) As and Sb concentration, respectively. In addition, antibiotic resistance genes were found to co-occur with metal resistance genes in the assembled bins. These findings might provide theoretical guidance for bioremediation of As and Sb co-contamination in alkaline environment.

Forest swamp succession alters organic carbon composition and survival strategies of soil microbial communities

Forest swamp ecosystems plays crucial role in the global carbon cycle. However, the effects of forest swamp succession on soil organic matter (SOM) and microbial community structure remain unclear. To determine the drivers of SOM change and soil microbial communities in forest swamp succession, a 'space instead of time' approach was used. Soil samples from 0 to 40 cm were collected along forest swamp (early stage), dried-up forest swamp (middle stage), and forest (late stage) ecosystems. Our findings reveal that as succession progresses, the relative content of aromatics decreases and SOM undergoes a transition towards a more readily degradable form. These changes affect soil carbon sequestration and nutrient availability. Bacterial diversity was significantly influenced by succession and changes in soil depth, with fungi exhibiting higher resilience. Soil properties and environmental conditions exert influence over the structure and function of microorganisms. As succession occurred, microbial interactions shifted from cooperation to competition, with bacteria displaying a deterministic distribution pattern and fungi exhibiting a random distribution pattern. SOM quality plays a key role in shaping microbial communities and influencing their growth strategies. Microorganisms are the major drivers of soil respiration, with K-strategist dominated communities in early succession exhibiting slower degradation rates, whereas r-strategists dominated in later stages, leading to faster decomposition.

Life After Retirement: Exploring the Survival Strategies of SSNIT Pensioners in the Greater Accra Region of Ghana

Ghana's elderly population represents about 6.7% of the national populace. They comprise persons aged sixty years and above, including retirees. The main source of income for some of these individuals, particularly those who worked in the formal sector is the monthly pension they receive as compensation for contributing to Ghana's public pension scheme known as the Social Security and National Insurance Trust (SSNIT) while they were working. However, some beneficiaries of the scheme have raised concerns about the inadequacy of the pension income. Old age is accompanied by other social, economic, and health issues that tend to be detrimental to one's well-being. In this study, the survival strategies adopted by SSNIT pensioners to assuage the challenges they encounter, mainly due to inadequate pensions were explored. The mixed-methods research design was employed to gather data from 437 respondents. Whereas the quantitative findings were analyzed via the Stata software, the framework approach was adopted to analyze the qualitative data. The majority (78.7%) of the pensioners indicated that their pensions were insufficient to meet their needs. In their quest to address the challenges confronting them, the pensioners either adopted survival strategies they considered suitable or resorted to other non-prioritized coping mechanisms perceived to be relevant only in times of urgent necessity. Based on the findings of the study, some recommendations for policy and practice were presented.

Rhizosphere microbial community composition and survival strategies in oligotrophic and metal(loid) contaminated iron tailings areas

In this study, the metal(loid) fractions in two alkaline iron tailings areas with similar physico-chemical properties and the enrichment ability of dominant plants in these areas were investigated. Additionally, high-throughput sequencing and metagenome analysis were used to examine the rhizosphere microbial community structures and their strategies and potential for carbon fixation, nitrogen metabolism, and metal(loid) resistance in mining areas. Results showed that Salsola collina, Setaria viridis, and Xanthium sibiricum have strong enrichment capacity for As, and the maximum transport factor for Mn can reach 4.01. The richness and diversity of bacteria were the highest in rhizosphere tailings, and the dominant phyla were Proteobacteria, Actinobacteria, Ascomycota, and Thaumarchaeota. The key taxa present in rhizosphere tailings were generally metal(loid) resistant, especially Sphingomonas, Pseudomonas, Nocardioides, and Microbacterium. The reductive citrate cycle was the main carbon fixation pathway of microorganisms in tailings. Rhizosphere microorganisms have evolved a series of survival strategies and can adapt to oligotrophic and metal(loid) polluted mining environments. The results of this study provide a basis for the potential application of plant-microbial in situ remediation of alkaline tailings.

Unraveling diverse survival strategies of microorganisms to vanadium stress in aquatic environments

Worldwide vanadium contamination is posing serious risks to ecosystems. Although abilities of microbial communities to cope with vanadium stress using specific survival strategies have been reported, little is known regarding their relative importance and the underlying detoxification/tolerance mechanisms. Herein, we investigated the potential survival strategies of microbial communities and associated pathways in aquatic environments based on geochemistry and molecular biology. High vanadium content was observed for both water (12.6 ± 1.15 mg/L) and sediment (1.18 × 10³ ± 10.4 mg/kg) in the investigated polluted stream. Co-occurrence network investigation implied that microbial communities showed cooperative interactions to adapt to the vanadium-polluted condition. Vanadium was also characterized as one of the vital factors shaping the community structure via redundancy analysis and structural equation models. Based on the metagenomic technology, three survival strategies including denitrification pathway, electron transfer, and metal resistance in innate microbes under the vanadium stress were revealed, with comprehensively summarized vanadium detoxification/tolerance genes. Remarkable role of electron transfer genes and the prevalent existence of resistance genes during detoxifying vanadium were highlighted. Overall, these findings provide novel insights into survival strategies under the vanadium contamination in aquatic environments, which can be of great significance for the identification, isolation, and application of vanadium reducing bacteria in vanadium bioremediation.

Metagenome-Assembled Genomes from Monte Cristo Cave (Diamantina, Brazil) Reveal Prokaryotic Lineages As Functional Models for Life on Mars

Microbial communities have been explored in various terrestrial subsurface ecosystems, showing metabolic potentials that could generate noteworthy morphological and molecular biosignatures. Recent advancements in bioinformatic tools have allowed for descriptions of novel and yet-to-be cultivated microbial lineages in different ecosystems due to the genome reconstruction approach from metagenomic data. Using shotgun metagenomic data, we obtained metagenome-assembled genomes related to cultivated and yet-to-be cultivated prokaryotic lineages from a silica and iron-rich cave (Monte Cristo) in Minas Gerais State, Brazil. The Monte Cristo Cave has been shown to possess a high diversity of genes involved with different biogeochemical cycles, including reductive and oxidative pathways related to carbon, sulfur, nitrogen, and iron. Three genomes were selected for pangenomic analysis, assigned as Truepera sp., Ca. Methylomirabilis sp., and Ca. Koribacter sp. based on their lifestyles (radiation resistance, anaerobic methane oxidation, and potential iron oxidation). These bacteria exhibit genes involved with multiple DNA repair strategies, starvation, and stress response. Because these groups have few reference genomes deposited in databases, our study adds important genomic information about these lineages. The combination of techniques applied in this study allowed us to unveil the potential relationships between microbial genomes and their ecological processes with the cave mineralogy and highlight the lineages involved with anaerobic methane oxidation, iron oxidation, and radiation resistance as functional models for the search for extant life-forms outside our planet in silica- and iron-rich environments and potentially on Mars.

How Do the Urban Poor Survive? A Comparative Ethnography of Subsistence Strategies in Argentina, Ecuador, and Mexico

Drawing on ethnographic data collected in three informal communities, one in Argentina, one in México, and one in Ecuador, we address the long-standing question posed by Larissa Lomnitz's and Carol Stack's now-classic studies of how impoverished people not only survive but what strategies they adopt in an attempt to build a dignified life. By focusing on the diversity of strategies by which the urban poor solve the everyday problems of individual and collective reproduction, we move beyond the macro-level analysis of structural constraint and material deprivation. Our findings show a remarkable continuity in the difficulties residents of these informal communities confronted and the problem-solving strategies they resorted to. We found that networks of kin and friends continue to play a crucial role in how poor people not only survive but attempt to get ahead. Additionally, we highlight the role of patronage networks and collective action as central to strategies by which the urban poor cope with scarcity and improve their life chances, while also paying close attention to ways in which they deal with pressing issues of insecurity and violence. The paper shows that poor people's survival strategies are deeply imbricated in routine political processes.

Freezing: how do water mites (Acari: Hydrachnidia) survive exposure to sub-zero temperatures?

Until now, very little is known about the ability of adult and deutonymph water mites (Acari, Hydrachnidia) to survive in sub-zero temperatures. Information concerns mainly water mites from vernal astatic waters, and the knowledge has never been experimentally verified. To determine the sensitivity of water mites to freezing, experiments were conducted on (1) the impact of acclimatization, (2) temperature, and (3) duration of freezing on survival, (4) the survival rate of water mites from various types of water bodies, and (5) the survival rate of water mites from different climatic zones. The experiments were carried out in a phytotron chamber, and water mites were placed in containers (10 × 10 × 5 cm) filled with 4/5 of water for 10 specimens each. Water mites were identified to the species level after finishing the experiments. The temperature was lowered 1 °C every hour until the target temperature was reached. After a certain period of freezing (depending on the treatment) the temperature was raised by 1 °C every hour until it reached 4 °C. The time of the experiment was measured from the moment the desired temperature was reached (below 0 °C) until the ice thawed and the temperature of 4 °C was reached again. The highest survival rates had Limnochares aquatica, Piona nodata, Sperchon clupeifer and Lebertia porosa, followed by L. insignis, Hygrobates longipalpis, H. setosus, Limnesia undulatoides, Piona pusilla, Arrenurus globator, Hydrodroma despiciens, Piona longipalpis, Sperchonopsis verrucosa, Unionicola crassipes and Mideopsis crassipes; no specimens of Torrenticola amplexa survived. The following conclusions were drawn: (1) water mites can survive freezing to -2 °C, lower temperatures are lethal for them; (2) they survived better the short period of freezing (24-48 h) than the long period (168 h); (3) resistance to freezing seems to be an evolutionary trait of individual species, only partly related to the living environment; and (4) freezing survival rates are linked to the region of Europe and are much lower in Southern than in Central Europe.

Research on the biology and ecology of the harmful algal bloom species Phaeocystis globosa in China: Progresses in the last 20 years

Chinese researchers have made substantial progresses in research on the harmful algal bloom (HAB) species Phaeocystis globosa since the first P. globosa bloom outbreak in the Chinese coastal waters in 1997. However, as many results, especially the earlier ones, were published in non-English literature, much of the research on P. globosa biology, ecology, and biogeochemistry made by Chinese researchers have been unknown to colleagues from other countries. We review current knowledge on taxonomy, morphology, genetics, physiology, survival strategies and mitigation of P. globosa gained by Chinese researchers from the past two decades. P. globosa is the only Phaeocystis species that causes blooms in the Chinese waters, although other Phaeocystis species including P. jahnii and P. cordata have been detected in Chinese coastal regions. P. globosa has a complex life history with at least two morphotypes including a haploid flagellate and a diploid colonial cell. Colonial P. globosa blooms typically occur in winter after a diatom bloom in coastal waters of the South China Sea. P. globosa in Chinese coastal waters usually has extremely large colonial sizes, up to 3 cm in diameter, an order of magnitude greater than that observed in European coastal waters. The development of giant colonies is associated with enhanced sinking rate, limited nutrient diffusion, as well as decreased stability of colonies. The Chinese P. globosa strains also showed strong genetic diversity and physiological plasticity, being able to grow and develop into colonies at higher temperature and irradiance relative to that in European waters. High genetic diversity of P. globosa was revealed by developing high-resolution and high-specificity molecular markers including Phaeocystis globosa chloroplast 1 (pgcp1). Due to the severe impact of P. globosa on ecology and economy, much effort has been made to mitigate P. globosa blooms including the application of modified clays. Overall, P. globosa in the Chinese waters demonstrate unique genetic, phenotypical and physiological features that differ from P. globosa in other ocean regions. Further studies are needed to explore how environmental factors trigger the occurrence of P. globosa blooms and ascertain the impact of P. globosa blooms on the environment.

The classification of bacterial survival strategies in the presence of antimicrobials

The survival of bacteria under antibiotic therapy varies in nature and is based on the bacterial ability to employ a wide range of fundamentally different resistance mechanisms. This great diversity requires a disambiguation of the term 'resistance' and the development of a more precise classification of bacterial survival strategies during contact with antibiotics. The absence of a unified definition for the terms 'resistance', 'tolerance' and 'persistence' further aggravates the imperfections of the current classification system. This review suggests a number of original classification criteria that will take into account (1) the bacterial ability to replicate in the presence of antimicrobial agents, (2) existing evolutionary stability of a trait within a species, and (3) the presence or absence of specialized genes that determine the ability of a microorganism to decrease its own metabolism or switch it completely off. This review describes potential advantages of the suggested classification system, which include a better understanding of the relationship between bacterial survival in the presence of antibiotics and molecular mechanisms of cellular metabolism suppression, the opportunity to pinpoint targets to identify a true bacterial resistance profile. The true resistance profile in turn, could be used to develop effective diagnostic and antimicrobial therapy methods, while taking into consideration specific bacterial survival mechanisms.

Bacterial Predation on Cyanobacteria

Predatory bacteria gained interest in the last 20 years. Nevertheless, only a few species are well characterized. The endobiotic predator Bdellovibrio bacteriovorus invades its prey to consume it from the inside, whereas Myxococcus xanthus hunts as a whole group to overcome its prey. Both species were described to prey on cyanobacteria as well. This minireview summarizes the findings of the last 20 years of predatory bacteria of cyanobacteria and is supplemented by new findings from a screening experiment for bacterial predators of the model organism Anabaena variabilis PCC 7937. Known predatory bacteria of cyanobacteria belong to the phyla Proteobacteria, Bacteroidetes, and Firmicutes and follow different hunting strategies. The underlying mechanisms are in most cases not known in much detail. Isolates from the screening experiment were clustered after predation behaviour and analyzed with respect to their size. The effect of predation in high nitrate levels and the occurrence of nitrogen-fixing cells, called heterocysts, are addressed.

Polyhydroxybutyrate: A Useful Product of Chlorotic Cyanobacteria

Polyhydroxybutyrate (PHB) is a carbon polymer with diverse functions, varying greatly on the organism producing it. This microreview describes the current knowledge about PHB metabolism, structure, and different physiological roles with a special focus on cyanobacteria. Despite the physiological function of PHB in the cyanobacterial phylum still being unknown, these organisms provide the unique opportunity to directly convert atmospheric CO2 into bioplastic using a solar-based process. Recent research on PHB metabolism in the cyanobacterial model organism Synechocystis revealed a sophisticated control of PHB granule formation. Novel insights about the metabolic background of PHB synthesis resulted in the engineering of the first cyanobacterial superproducer strain.

miRNA-based heavy metal homeostasis and plant growth

Plants have been naturally gifted with mechanisms to adjust under very high or low nutrient concentrations. Heavy metal toxicity is considered as a major growth and yield-limiting factor for plants. This stress includes essential as well as non-essential metals. MicroRNAs (miRNAs) are known for mediating post-transcriptional regulation by cleaving transcripts or translational inhibition. It is commonly agreed that an extensive understanding of plant miRNAs will significantly help in the induction of tolerance against environmental stresses. With the introduction of the latest technology like next generation sequencing (NGS), a growing figure of miRNAs has been productively recognized in several plants for their diverse roles. These miRNAs are well-known modulators of plant responses to heavy metal (HM) stress. Data regarding metal-responsive miRNAs point out the vital role of plant miRNAs in supplementing metal detoxification by means of transcription factors (TF) or gene regulation. Acting as systemic signals, miRNAs also synchronize different physiological processes for plant responses to metal toxicities. In contrast to practicing techniques, using miRNA is a greatly helpful, pragmatic, and feasible approach. The earlier findings point towards miRNAs as a prospective target to engineer heavy metal tolerance in plants. Therefore, there is a need to augment our knowledge about the orchestrated functions of miRNAs during HM stress. We reviewed the deterministic significance of plant miRNAs in heavy metal tolerance and their role in mediating plant responses to HM toxicities. This review also summarized the topical developments by identification and validation of different metal stress-responsive miRNAs.